Retainer



1951 'A. F. GATTIKER, JR. ETAL 2,579,382

4 RETAINER x Filed Dec. 4, 1948 l8 3 h, l9 R1; 5 E 2 I8 I 22 INVENTORS ALBERT F-GATTIKER JR AND ALFRED D.KARR

THEIR A ORNEY- Patented Dec. 18, 1951 *AlbertF. Gattiker, Jr., Athens, Pa., and Alfred n. 1 r Karr, Newark, N, J., assignors to Ingersolli Rand Company, New York, N. Y., a corporation 1 of New Jersey Applicant December 4, 1948, Serial No. 63,542

This invention relatesto retainers" and more particularly to such a'device used as means for retaining the anvil'on the spindle of wrenches of the type in which the spindle moves longitudinally with respectto' the motor forengagem'ent and disengagement therewith. Experience has shown that in wrenches of the type referred to and'particularly'impact wrenches,

the anvilmust be engaged against -longitudinal movement with respect to the spindle in order to prevent partial disengagement of the anvil and hammer jaws and otherwise prevent erratic operation of the wrench. It is, accordingly, one object of this invention to secure the anvil to the spindle of an impact wrench against such motion in a relatively simple but efi'icient manner.

Heretofore, such means, in general, comprised some type of pin inserted in a slot in the] anvil andhaving one end extending into anannular groove formed around the spindle and having the other end flush with the outer periphery of the anvil and held in position by the bearing material in which the" anvil rotated. Such an arrangement entailed several disadvantages as for example, the inner end o'f'the pin would become peened over during. the operation of the wrench thereby making it diificult ,to remove the pin and, further, the outer end of. the pin had a tendency to wear a groovei'n the bearing material for the anvil. It is, therefore, av further object of our invention to eliminate any possibility of wear between the retaining means and the members which they serve to engagenamely, the spindle-to the anvil. Y

Another object of this invention is to provide asecuring means which may be readily removed from its engaging position.

Other objects of this invention will be obvious from the following description andassociated drawing in which: i v i Figure 1 .is a vertical elevation, partly, in

section, of an impact wrench embodying the present invention,

Fig. 2 is a transverse view taken through Figure 1 along the line 2-2 looking in the direction of the arrows and shows the construction of the means for securing the anvil to the spindle of the wrench,

Fig." 3"isa vertical elevation, partly in section, showing the securing means in a disengagedposition',

Fig. 4' is a transverse view taken through Figure 'i-along'the line 4+4 looking in the direction of the arrows, of the clutch arrange- 4Claims.. (01. 287- 419) ment whereby power is transmitted from the motor to the spindle of the wrench, and I Fig. 5 shows an alternate construction of the means for'securing the anvil to the spindle.- Referring to the drawing, [0 indicates, in general, an impact wrench embodying apreferred form of the means for securing the anvil H to the spindle I2. Impact wrenches of the type to which this invention-appertains are generally utilized under circumstances where a plurality of nuts are tightened in rapid succession andit is, therefore, adapted to'be moved from one nut to the next without shutting off its motor. -In this manner, the socket can be removed from the nut and adapted to the following nut, or any other member it may be utilized to rotate, Without'the loss of time entailed in allowing the motor to stop between tightening operations; "Accordingly', the driving-motor (not shown) for the wrench runs continuously and is engaged and disengaged to the rotating member or spindle I? on which is mounted the hammer element 13 for intermittently rotating the anvil II which, in turn, rotates the socket -l4 engaging the nut 15. Q

Such engagement and disengagement of the spindle to the motor by longitudinal movement of the spindle [2 with respect to the motor is imparted bythe operator of the tool in the operation of tightening or loosening the nut." That is, after the socket I4 has been adapted to the nut IE, or is otherwise held againstendwise movement, any longitudinal movement of the motor thereafter in the jjdirec'tion of its work will serve' to engage the spindle to the motor and any longitudinal movement away from'it sf work as is. required in order to remove the socket M from "the nut 15, will serve to' disengage th e spindle-from the motor. It is due'to'this rela'-' tive movement of the'spindle with respect'to the motor that the need arises for a means for'retaining the anvilagainst movement with respect to the spindle. The wrench i0 is, acordin'gly, provided with the unique retaining means; designated, in general, by llfl, that prevents .llongitudinal movement and permits rotary move ment between the members which it engages. More specifica1ly, the impact wrench l9 comprises a motor housing 16 to which is bolted a casing l'l into, which projects a spindle or arbor 18 through a perforation .9 in the plate 8 which forms a closure for the back end of the casing H. The spindle: I8 is rotated 'byfthe motor through a gear train (not shown) and has a reduced extension is arranged telescopically in l8 which cooperate with another set of jaws-I also 180]degrees apart, mounted on the rearward end of the spindle I2. It will be noted that the jaws 233 are of somewhatvless vwidth than the,

jaws 22in order to permit easy and sure engage-e ment of the clutch. In the arrangement shown} the clutch members 22 and 23 are constantly urged into the disengaged positionby means of:

a spring 24 interposed between the bottom of the bore and the lower or free end of the extension 19. Inasmuch as relative rotation occurs between the spindle I2 and the spindle [8, the

free end'of the extension 19 is recessed to receive a ball interposed between; the spring and the spindle to minimize, the friction therebetween.

Lubrication of the ball is facilitated by means of a-passage 23 in. the spindle through which a lubricant may be passed from the gear case (not shown) V Loosely encirclingthe spindle i2 is the tubular shaped hammer element [3 having an internal flange 'm atthe lower or forward portion thereof on'which seats aspring 29, the other end of whichbears against a thrust bearing 33 mounted on the rearward end of the spindle l2 and held against rearward movement by flange 3 I on the spindle l2. The width of the members defining the races for the bearing are so designed as to maintain a sliding fit between the periphery" of thebearing 30 and the hammer element l3. Withthis construction and arrangement, the bearing 30 serves the additional purpose of guid ing the hammer element l3.

Immediately forward of the flange 28 are the forward ends of the races 32 which spiral rearwardly in the periphery of the spindle 12. Balls 33 are supplied for the races 32 which are of greater diameter than the depth of the races 3:23

and, therefore, protrude into the path of the flange 28. With this arrangement, whenever the resistance to rotation of the anvil ll exceeds some predetermined value, as when the nut E51 is" seated, the speed of rotation of the'anvil will S1ow down whereas the motor speed tends to remain relatively constant. This causes the spindle [2 to rotate relative to the anvil II and the hammer l3 engaged thereby. 'Inasmuch as the balls 33 are held against rotational and ion gitudinal movement relative to the hammer l3 by the flange 28, the relative rotation-between theseelements drives theballs' 33 back along t rev races'32 moving the hammer longitudinally relaf tive to the spindle I2. Such movement o'f-the hammer compresses the spring 29 and disen gages the jaws'34'and'3li.

' A't this time the balls 33 are at or near the rearward end of the races 32; hence, whenthe jaws 34 and are'disen'gaged; the spring 29 will expand driving the-hammer forwardly, and theballs riding forward in the races 32 will impart'fo'rward rotational movementto the hammer relativet'o the spindle l2 and anvil I l; Of

course, the hammer is also rotatedby thespindle l2"; .As the balls 33 near the forward ends of the races 32 thejaws 35 are moved into alignment with thejaws .34 so that the hammer l3 strlk'esa-bloiv'on the'anvil ll.

In order to permit the wrench to work equally well in either direction, as for loosening the nut IS, the races 32 are V-shaped with the point of the V located immediately forward of the flange. Thus, when the rotation of the motor is reversed, rotation of the spindle 12 relative to the hammer l3 will cause the balls to ride backwardly along the other leg of the V to disengage the hammer in the manner previously described.

The anvil H which serves to transmit the rotary movement of the hammer [3 to the nut 15 -01 other member to be rotated is arranged telescopically on the forward end portion of the spindle J2 and journaled in the forward end of the casing H. A replaceable bearing material is interposed between the anvil H and the casing l'l which serves to eliminate the wear between the casing and the body portion of the anvil and the forward edge of the wings 21 spaced 180 degrees apart on the rearward end of the anvil. Mounted on and extending rearwardly' of the wings 27 are jaws 34 that engage a similarset of jaws 35 formed on the forward end of the hammer I3 for transmitting the blow energy of the hammer 13 to the anviL' It is readily apparent that during the opera-f tion of the wrench, due to the violent vibratory action of the hammer l3 with respect tothe'i spindle l2, the spindle" ['2 will tend to movelongig' tudinally relative to 'the anvilv ll resulting in partial disengagement of the jaws 34 and 35 In order to obviate this disadvantage, means is provided which engages the spindle to the anvil to prevent longitudinal movement therebetween' and thereby assuring the proper matingrelation between the jaws 34'and 35 at all times. U

In the preferred form shown, this means comprises an annular groove 36 in the periphery of V thelbore 31 encircling the spindle I2."The' depth of the bore 31' is such that when the end of the spindle l2 rests on the bottom of the bore 3? and the hammer is in its lowermost position, the jaws 34 and 35 are positioned to engage fully. When the'spindle I2 is this position, the cavities or transverse passage 38provided'in the spindle l2 aligns with the groove 36- andanti friction members, such as the balls 39, are provided in the passage 38 whichextend' into the groove 33' to prevent longitudinal movement of the anvil with respect'to'the spindle 62 but which permits unrestricted rotary movement therebetween. -'In order to attain positive engagement between-the anvil ll and the spindle l2, a means isprovided for urgingthe balls 39 into the groove 36 which; in the" form of the invention shown, comprises a pin 40 inserted in a bore 4i co-extensive with, but of smaller diameter than, the central bore 26in the spindle 'lZi- A head 42 is provided in the rearward end of the pin 40 which limits'forward-movement of thepin and'rearward movement of the pin is restricted by the spring 26 which rests thereon. s

Thus it may be'seen by the proper choiceof the size of the balls 39, i. e.,-having a: diameter substantially equal to the depth-of the groove 35 plus the thickness of the-wall defining the cavities 38, the'bal1s 39 will'be forced intoposi tion to engagethe anvil II to the' spindle ,l2 whenever the pin 49 is interposed between the balls as. v I

With this arrangement,- in order to disengage the spindle 12 from the anvil H, it is merely necessary to retract the pin and therebyre lease the balls to recede into the cavities or passage38 to free the spindle to be withdrawn from he anvi W 1 r rx P e ent. t e a l 19 .11

receding too far into the cavities 38 and subsequently falling into the bore 4|, or otherwise making it difilcult to adapt the hammer to the spindle, the inner ends of the cavities are reduced somewhat (see Figure 3) so as to limit the inward movement of the balls 39, or in the alternate construction shown in Figure 5 a bore Al is formed of less diameter than the balls 39.

It is now obvious to those skilled in the art that the present invention provides a simple and effective means whereby an anvil may be engaged to and disengaged from the spindle of an impact wrench, and the like, and which will permit relatively uninhibited rotary movement therebetween. It will be noted, further, that the arrangement shown eliminates the need for any transverse passages in the anvil II with their attendant weakening effect on a member subject to high strain, as an impact.

While we have shown and described specific forms of our invention, it is to be understood that various changes and modifications may be made without departingfrom the spirit of the invention as set forth in the appended claims.

We claim:

1. A retainer comprising, two relatively rotating members, one slidably mounted within the other, the outer of said members having a groove therein, the inner member having a cavity therein opposite the groove, an anti-friction member in the cavity and of greater width than the depth of the cavity, said inner member having a bore therein intersecting the cavity and of less width than the width of said antifriction member, and means within the bore for holding said anti-friction member in the groove to prevent longitudinal movement between said relatively rotating members.

2. In an impact wrench of the type having a longitudinally acting clutch for the motor, a spindle adapted to be engaged to the motor by the clutch, an anvil slidably mounted on an end oi. the spindle, the anvil having a groove therein encircling the spindle, the spindle having a cavity therein opposite said groove, 9. ball in the 5 2,255,695

cavity extending into said groove and being retractable into the cavity, said spindle having a passage therein in communication with the cavity, a pin having a loose fit in said passage for holding the ball in said groove, and a spring in said passage for holding the pin in the passage and for disengaging said clutch.

3. A retainer for a pair of telescopically arranged members, the outer member having a groove therein, the inner member having a longitudinal bore therein and a cavity communicating with said bore and groove, an antifriction member positioned in said cavity and extending into said groove, a rod extending slidably into the bore for moving said antifriction members into the groove, and means on the inner member to prevent said antifriction member from passing through said bore when the rod is withdrawn therefrom.

4. A retainer for a pair of telescopically arranged members, the outer member having a groove therein, the inner member having therein a longitudinal bore and a cavity communicating with said bore and groove, an antifriction member positioned in said cavity and extending into said groove, a rod extending slidably into the bore for moving said antifriction members into the groove, said rod being of substantially uniform diameter throughout that portion of its length extending into said bore, and means on the inner member to prevent said antifriction member from passing through said bore when the rod is withdrawn therefrom.

ALBERTF. GATTIKER, JR. ALFRED D. KARR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,881,728 Levedahl Oct. 11, 1932 Bull Sept. 9, 1941 

